This invention is in the chemical laser field and more particularly it is in the field of chemical oxygen-iodine laser (COIL) devices. COIL devices in the past have typically employed chemically produced singlet delta, molecular oxygen O.sub.2 ('.DELTA.), to dissociate molecular iodine, I.sub.2, into atomic iodine, I, and excite the atomic iodine to a lasing state. An example of one such laser is disclosed in an article by Benard et al appearing in Applied Physics Letters, Vol. 34, No. 1, 1, Jan. 79. The Benard et al article includes a disclosure of a singlet delta oxygen generator that functions by bubbling chlorine gas, Cl.sub.2, through a hydrogen peroxide, H.sub.2 O.sub.2, and sodium hydroxide, NaOH, mixture.
A more efficient excited oxygen generator is disclosed in a U.S. Pat. No. 4,558,461 to McDermott et al and assigned to the United States Government. The excited oxygen generator employed in the McDermott et al patent utilizes a tubular reaction chamber. Chlorine gas and a liquid mixture of hydrogen peroxide and sodium hydroxide are introduced into a tubular reaction chamber. The interior walls of the reaction chamber are wetted by the liquid during operation and the chlorine gas flows through the center of the tube. This results in a gas/liquid interace of circular cross-section that is an efficient producer of singlet oxygen. The prior art discussed above discloses reacting molecular iodine and singlet oxygen to form atomic iodine which is subsequently excited to a lasing state by the singlet oxygen. The molecular iodine is provided by flowing an Argon carrier gas over I.sub.2 crystals to seed the carrier gas with I.sub.2 vapor.
Chemically pumped iodine lasers have been shown to be efficient scaleable devices capable of producing continuous wave (CW) operation over long periods at significant output powers. However a significant disadvantage to present COIL systems that use molecular iodine, I.sub.2, as the source for atomic iodine, I, is the lower vapor pressure of I.sub.2. If for example, supersonic operation of a coil were desired, delivery of I.sub.2 at pressures exceeding its vapor pressure in the gas stream would be required. Under these conditions of increased pressures, Van der Waals' complexes of I.sub.2 can form and lead to condensation of the I.sub.2 that results in I.sub.2 particle formation, liquid or solid, that seriously degrades laser operation. It is possible that future COILs may be high pressure devices employed in laser weapon systems, or as a laser driver for inertial confinement fusion. In these applications condensation could be a serious problem if known methods were used to obtain atomic iodine.